The walking speed ratio of a and B is 13:11. If a and B start from a and B at the same time and walk in opposite directions, they will meet in 0.5 hours. If they walk in the same direction, it will take () hours for a to catch up with B A. 4.5B. 5C. 5.5D. 6

The walking speed ratio of a and B is 13:11. If a and B start from a and B at the same time and walk in opposite directions, they will meet in 0.5 hours. If they walk in the same direction, it will take () hours for a to catch up with B A. 4.5B. 5C. 5.5D. 6

Suppose that the speed of a is 13 kilometers per hour, and that of B is 11 kilometers per hour. According to the meaning of the question, the distance between the two places is: (13 + 11) × 0.5 = 24 × 0.5 = 12 (kilometers) and a needs to catch up with B: 12 △ 13-11 = 12 △ 2 = 6 (hours)